When short distance communications is applied in an intelligent transport system, by taking an emergency service, such as an accident warning, as an example, all vehicles need to be installed with a short distance communications module, so as to complete reporting an emergency message through communication and forwarding between vehicles during a warning, or a large number of road-side communication devices are laid out on both sides of a road, so as to complete reporting an emergency message through communication and forwarding between a vehicle and a road-side communication device. However, because the short distance communications has a relatively high requirement for a communication distance, it is hard to ensure communication quality.
A UMTS (Universal Mobile Telecommunication Systems) has advantages of seamless coverage and convenient layout, which can meet requirements for a communication distance and communication quality, and therefore, in the prior art, a warning message can be reported by adopting the UMTS. When an emergency message is reported, an accident UE (User Equipment) needs to report the emergency message to a network side device, and the network side device reports it to a server of a transport control management center through a CN (Core Network), and then the server delivers the emergency message to a vehicle-mounted UE in other normally running vehicles one by one so as to play a role of warning.
In a process of reporting an emergency message, the emergency message needs to be uploaded to a CN by a local network side, and then transmitted to a server of a management center, and the server of the management center delivers the emergency message to UEs one by one. A whole transmission process lasts for seconds, while for an emergency service, a delay of reporting an emergency message is generally required within milliseconds. Therefore, it is difficult for a current transmission process of an emergency message to meet a requirement for a delay of a system.